Adjustable tensioning means for tools



Nov S, W6 H. B. GIBSON 3, fi

ADJUSTABLE TENSIONING MEANS FOR TOOLS Filed July 20, 1964 INVENTOR H. B.G/BSO/V ATTORNEY United States Patent Ofllice 3,284,076 Patented Nov. 8,1966 3,284,076 ADJUSTABLE TENSIONING MEANS FOR TOOLS Howard B. Gibson,Glen Ridge, N..l., assignor to The Thomas & Betts C0., Elizabeth, N.J.,a corporation of New Jersey Filed July 20, 1964, Ser. No. 383,802Claims. (Cl. 267-1) This invention relates to adjustable tension meansfor use in tools having an element or elements on which tension is to beexerted. Pursuant tothe invention novel adjustment tension means areprovided, enabling tension to be slowly or rapidly achieved, at the willof the user, in a convenient manner, as, for example, to adapt the toolfrom heavy to light duty work, and providing an infinite range ofadjustments for various uses and conditions. Thus rapid adjustment, or,selectively minute adjustment, may be attained, as. desiredin anefficient and highly effective manner.

The drawings, illustrating procedures and devices useful in carrying outthe invention, and the description below, are exemplary only of theinvention, which shall be deemed to cover all other devices andprocedures coming within the scope and purview of the appended claims.

In the drawings, wherein similar reference characters indicate likeparts:

FIG. 1 is a side elevational view of a tool provided with the adjustabletensioning means of the invention,

FIG. 2 is a fragmentary, partly sectional, view of a portion thereof,

FIG. 3 is a bottom plan view, taken at line 3-3 of FIG. 2,

FIG. 4 is a fragmentary elevational view thereof, and

FIG. 5 is a fragmentary perspective view of parts thereof.

As above noted, the invention is adapted for applying adjustable tensionto tools, for example, as shown in the drawing, having a first member orelement as to which adjustable tension is to be exerted. The element 10is a practical form of application of the invention, without limitingthe invention in any wise thereto; the invention is equally applicableto all other tool elements to be subjected to tension. The adjustabletension means of the invention is operable on the tension element 11 andmay comprise an axially movable part engaging said element 10, forexample the threaded pin 13 which passes through a slot 14 in the casing15 at one end and has complementary engagement at the other end with alink member 12 secured to the tension element 11. Casing 15 housing theadjustable tension means, is provided at the end thereof (FIGS. 2 and 1)with said slotted portion 14 recessed as at 16, adapted to be engaged bythe complementary roller 17 to which the pin 13 is connected by a crosspin 18 or the like, the latter eccentrically journalled in the roller 17having (FIG. 5) a slot 19 receiving the pin 13.

The roller 17, as above noted circumferentially engages the recess 16 ofslot 14. By virtue of the eccentric mounting of roller 17 on pin 18 andits connection thus with the threaded pin 13, rotation of roller 17 inone direction will axially move the pin 13 relative to the axis of thecasing 15, to thus increase tension on tension member 10, and rotationof roller 17 in the opposite direction will decrease tension. Bearingsurface 20 of roller 17 serves at a stop engaging pin 13 on rotation ofthe roller, to limit such rotation in either (FIG. 1 or opposite)direction.

To achieve substantial changes in tension rapidly, the

roller 17 is moved completely away from the areuate portion 1 6 of thecasing 15 (as shown at 17a, FIG. 4). One may then rotate the pin 13rapidly to thread pin 13 in link 12 and thus achieve a very rapid orabrupt adjustment of the tension. As above noted, for achieving fineadjustments roller 17 may be slowly rotated. In either case, a marking21 on the link or other element 12 connected to the tension element 11may be read through a slot 22 (FIG. 4) in the casing 15 and on the scale23 marked on the casing providing for a constant reading of the degreeof tension exerted by the adjustable tension means 11, above described.

For illustration of one form of tension element 10 and withoutlimitation thereto, reference is made to FIG. 1 from which it will benoted that element 10 is there shown as a rocker arm pivoted as at 24and having a flanged part 25 to be engaged by a complementary flange 26of a cam plate 27 :pivotally mounted on the casing 15 as at 28, a pin 29connecting said cam plate 27 with a handle 30, which is connected by apin .31 to a plate 32 having a spring urged pawl 33 normally rotatedcounterclockwise by spring or other means to press a strap or the like34 against a flange 35 on plate 32. The pawl 33 is mounted on a pin 36on the plate 32, whereby the strap 34 will be normally held pressedbetween the pawl 33 and flange 35 and thus moved with movement of thehandle 30. The pin 31 passes through an arcuate slot 37 in casing 15.The handle 30 has a slot 38 through Which the pin 28 passes.

The handle 30 pivots on the pin 23 until the strap 34 resists furthermovement. The pin 31 then becomes the pivot point for the handle whoseupper end 29 then moves the cam plate 27 to lift or rotate the rockerplate 10. The point at which the resistance on the strap 34 becomessufficiently great to effect a shift in the pivot point for handle 30from 29 to 31 is predetermined by the tension exerted by the tensionelement 11 on the plate 10, this in turn being adjusted by theadjustable tension means of the invention.

As above noted, this illustration of a practical form to which theadjustable tension means of the invention may be applied is illustrativeonly and is not to be deemed limitative in any fashion.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a tool having a casing and a first member on which tension is tobe exerted, a tension member engaging said first member, said casinghaving a slot, means passing through the casing slot and engaging saidtension member, roller means eccentrically connected to said meanspassing through said slot and adapted to rotatably engage said casingwhereby, on rotation of said ro'ller means in engagement with thecasing, the means passing through the slot will be moved and the degreeof tension of the tension means may be varied.

2. In a tool as set forth in claim 1, said casing having an arouaterecess and said roller means so adapted to engage the casing by engagingsaid recess.

3. In a tool as set forth in claim 1, said means so passing through saidslot comprising an elongated pin, threadedly connected to the tensionmember, so that the degree of tension of the tension member may bevaried on rotation of the roller about the axis of the pin.

4. In a tool having a casing and a first member on which tension is tobe exerted, a tension member engaging said first member, said casinghaving a slot, means passing through the casing slot and engaging saidtension member, roller means connected to said means passing throughsaid slot and adapted to rotatably engage said casing whereby, onrotation of said roller means, in engage ment wit-h the casing, themeans passing through the slot will be moved and the degree of tensionof the tension means may be varied, said casing having an arcuate recessand said roller means adapted to so engage the casing by engaging saidrecess, complementary means on said means so passing through said slotand said tension member for adjusting the point of connection thereof,thereby adjustably so connecting the same so that on rotation of saidroller in the plane of its axis, the point of connection of the rollerWith the tension member may be adjusted.

5. In a tool having a casing and a first member on which tension is tobe exerted, a tension member engaging said first member, said casinghaving a slot, means passing through the casing slot and engaging saidtension member, a link connected to the tension member andcomplementarily threadedly engaging said means passing through the slot,roller means connected to said means References Cited by the ExaminerUNITED STATES PATENTS 2,599,403 6/1952 Martin 2671 2,735,669 2/1956Seiler 2671 2,891,784 6/1959 Taylor 267--1 ARTHUR L. LA POINT, PrimaryExaminer.

R. M. WOHLFARTH, Assistant Examiner.

1. IN A TOOL HAVING A CASING AND A FIRST MEMBER ON WHICH TENSION IS TOBE EXERTED, A TENSION MEMBER ENGAGING SAID FIRST MEMBER, AND CASINGHAVING A SLOT, MEANS PASSING THROUGH THE CASING SLOT AND ENGAGING SAIDTENSION MEMBER, ROLLER MEANS ECCENTRICALLY CONNECTED TO SAID MEANSPASSING THROUGH SAID SLOT AND ADAPTED TO ROTATABLY ENGAGE SAID CASINGWHEREBY, ON ROTATION OF SAID ROLLER MEANS IN ENGAGEMENT WITH THE CASING,THE MEANS PASSING THROUGH THE SLOT WILL BE MOVED AND THE DEGREE OFTENSION OF THE TENSION MEANS MAY BE VARIED.